1. Field of the Invention
The present invention relates to the field of payphones and, more particularly, to an automatic coin collection device for a payphone that is provided with no coin collection signal.
2. Description of the Related Art
Conventionally, a payphone installed in a telephone booth by a telephone company has the function of automatic coin collection after a telephone connection has been established thereby, starting to charge the caller. This function is available because the telephone switch provides a so called coin collection signal, which is an inverse polarity or 12/16 KHz coin collection signal, to the payphone when establishing the telephone connection. However, for private individuals or companies desiring to install payphones on private lines in stores, restaurants, cafeterias, or amusement centers, the coin collection signals are not provided by the telephone switch. Therefore, as shown in FIG. 4, the payphone 40 installed currently should have a pushbutton 41, such that the user can press the pushbutton 41 when a telephone connection is established, thereby accomplishing the function of coin collection. Such a coinbox payphone 40 is currently in use in many countries.
The use of the aforementioned coinbox payphone would not be satisfactory because users are not aware of the operating procedure. Generally, the user may operate the pushbutton 41 incorrectly, such as press it too early, too late, or even forget to press, which results in unnecessary conflicts between the user and the payphone owner. Even worse is that some users may intentionally use the payphone to make a phone call and listen to the message from an answering machine, or may maliciously operate the payphone to make phone calls without pressing the pushbutton (41). For these reasons, sales of this type payphone are greatly limited. As such, it may cause an economic loss to the payphone owner. Therefore, there is a need for the above payphone to be improved.
It is therefore an object of the present invention to provide an automatic coin collection device for a payphone to be used on a private line which has no coin collection signal. With this, the user can use the payphone to make a phone call without the need of pressing the pushbutton.
To achieve the above objects, there is provided an automatic coin collection device, which includes: a solenoid for being activated to collect coins so as to start to count time and begin telephone communication; a call tone detector connected to a telephone line for detecting a call tone on the telephone line; a voice detecting circuit connected to the telephone line for detecting a voice signal on the telephone line; and a micro-controller for performing an analysis based on the detecting results of the call tone detector and the voice detector circuit after a user has dialed the payphone to make a phone call, and for activating the solenoid to start to count time and begin telephone communication when a ring back tone on the telephone line disappears and a voice signal appears, or when no ring back tone is detected but a voice signal appears.
The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.